Its not underpowered for average users, but it’s not meant for professional uses beyond basic office work.
Similar to the mini they offer the Studio which doesn’t have a monitor built in https://www.apple.com/mac-mini/compare/?modelList=Mac-studio-2023,Mac-mini-M2
Then for the higher end uses they offer a more typical tower format https://www.apple.com/mac-pro/
If you want to play modern or even recent games and indulge your locked down metwork desires I recommend getting a secondary PC just for gaming and run a separate vlan to fully separate traffic from your existing setup. There’s really no realistic threat vector there barring a state level actor or something equally serious but I’m happy to be corrected.